1. Field of the Invention
This invention relates to a medical instrument which is inserted into a body cavity and performs a bending operation.
2. Description of Related Art
Laparoscopic operations are known in which, in performing a medical procedure of observing, treating, etc. an organ of the human body, instead of incising the abdominal wall widely, a plurality of orifices are opened in the abdominal wall and procedures are performed upon inserting a laparoscope, forceps, and other treatment instruments into the orifices. Such procedure provides the benefit of lessening the burden placed on the patient because only small orifices need to be opened in the abdominal wall.
In recent years, methods of performing procedures upon inserting a flexible endoscope via the mouth, nose, anus, or other natural orifice of the patient have been proposed as methods of further reducing the burden on the patient. An example of such procedures is disclosed in U.S. Pat. No. 5,458,131.
With this method, a flexible endoscope is inserted from the mouth of a patient, an opening is formed in the stomach wall, and a distal end part of the endoscope is fed into the abdominal cavity from the opening. Then while using the endoscope as a device for observing the interior of the abdominal cavity, desired procedures are performed inside the abdominal cavity using a treatment instrument inserted through the endoscope or a treatment instrument inserted from another opening.